PT110470B - TRIBOMETER, METHOD OF MEASUREMENT AND ITS USES - Google Patents

Abstract

THIS DISCLOSURE REFERS TO AN APPARATUS AND A METHOD FOR DETERMINING TRIBOLOGICAL PARAMETERS, IN PARTICULAR A BLOCK ON DISK TRIBOMETER COMPRISING THE FOLLOWING ELEMENTS: LOAD APPLICATION BAR (1), DRIVE ASSEMBLY (2), SUPPORT SAMPLE (3), ROTATING DISC (4) AND WEIGHT APPLICATION SUPPORT (5). IN PARTICULAR, THE TRIBOMETER FEATURES A MECHANICAL LOAD APPLICATION SYSTEM USING A BAR WITH A RATIO OF, FOR EXAMPLE, 1:4, WHICH IS USED FOR TESTS THAT REQUIRE A HIGHER LOAD. IT ALSO USES A SIMPLE SAMPLE HOLDER THAT ALLOWS EASY SAMPLES CHANGE AND RESTRICTS THE ROTATION OF SAMPLES DURING THE TESTING BECAUSE IT HAS TWO GUIDES.

Description

DESCRIPTION

TRIBOMETER, METHOD OF MEASUREMENT AND ITS USES

TECHNICAL DOMAIN

The present disclosure relates to a method and a tribometer apparatus for determining tribological parameters of a specimen or sample.

The tribometer of the present disclosure allows to determine the tribological values of a sample, such as the friction coefficient, the friction force and the wear volume of various materials, namely, metals, polymers, ceramics, composites, etc. It can be used in materials analysis, namely in mechanical construction and other applications.

BACKGROUND

A tribometer is a testing machine that measures tribological quantities, such as friction coefficient, friction force and wear volume, between two surfaces in contact. This machine is intended for. measuring the wear of materials. We can define wear as the progressive loss of material due to relative movement between the surface and the antagonist material. Wear is related to interactions between surfaces and, more specifically, the removal and deformation of material on a surface as a result of the mechanical action of the antagonist surface.

There are already on the market several tribometers with the most varied systems. However, one of the disadvantages of existing tribometers is that they do not allow testing under high and low loads, being limited to a limited set of predetermined loads.

These facts are described in order to illustrate the technical problem addressed by the present invention.

GENERAL DESCRIPTION

The present disclosure relates to a tribometer apparatus and a method for determining tribological parameters of a specimen or sample.

The tribometer of the present disclosure allows to determine the tribological values of a sample, such as the friction coefficient, the friction force and the wear volume of various materials, namely, metals, polymers, ceramics, composites, etc. It can be used in materials analysis, namely in mechanical construction and other applications.

The measurement method is based on the loss of mass (weighing before and after testing the specimen) or on the dimensional measurement of the worn shape of the specimen, determining the lost volume and, consequently, the mass, knowing the specific weight of the material under test.

The present disclosure presents a mechanical load application system using a bar that allows a load ratio, for example 1:4, which can be used for tests that require a higher load.

The present disclosure presents a sample holder that allows for the ease of changing samples and restricts their rotation during the test by having two guides.

The present disclosure refers to a block-on-disk tribometer for wear tests, which allows to carry out tests on various materials, namely, metals, polymers, ceramics, composites, etc. The specimen under test may preferably have a parallelepiped shape. The present tribometer also has the versatility of being able to have other contact configurations, namely disk-disk and sphere-disk.

In one embodiment, a pin-on-disk tribometer for wear testing of materials, namely metals, polymers, ceramics, composites, etc., is described. The tribometer uses a mechanical load application system using a bar with a ratio of, for example, 1:4, which is used for tests that require greater load or withdrawal for low loads (using in the latter case direct load through weights). The 1:4 ratio proved to be a good compromise between a practical dimension and an adequate leverage effect.

In one embodiment, the tribometer of the present disclosure describes a simple sample holder that allows for ease in changing samples and restricts their rotation during testing by having two guides.

In one embodiment, the mechanical load application system uses a bar that allows a load ratio of 1:4, which is used for tests that require a higher load. It also uses a simple sample holder that allows for easy change of samples and restricts their rotation during the test as it has two guides.

A tribometer for measuring tribological parameters of a specimen by wear tests is described, comprising:

a wear disc for contacting the specimen, a specimen holder for guiding the specimen over the wear disc;

a load-applying bar hinged between two positions, a first position for applying load on the specimen against the wear disc, and a second position withdrawn from the specimen, a disc drive motor means.

According to one embodiment, the articulated bar has an arm which extends beyond the specimen to apply leverage over said specimen.

According to one embodiment, the disk drive motor means comprises a shaft motor for rotating the wear disk.

According to one embodiment, the articulated bar has an arm that extends beyond the specimen, configured to receive a weight to apply an additional leverage load on said specimen.

According to one embodiment, the articulated bar has an arm which extends beyond the specimen with a weighting support for receiving a weight for applying an additional leverage load on said specimen.

According to one embodiment, the specimen holder comprises two guides to guide the specimen slidably over the wear disc to prevent rotation of the specimen when subjected to wear by the disc.

According to one embodiment, the load-applying bar has a load ratio, between the load position on the specimen and the dimension of the lever arm of the same bar, from 1:3 to 1:5 ₍ in particular 1:4 .

According to one embodiment, the loading bar is made of steel.

One embodiment comprises an element of circular section for transmitting load from the bar to the specimen.

One embodiment comprises support for applying weights on said specimen.

A method of operating the tribometer according to any of the described embodiments, comprising;

apply load on the specimen against the wear disc, where the load application bar is pivoted to one of two positions, a first position for applying a greater load of the specimen against the wear disc, or a second position removed from the specimen for applying a lower load of specimen against the wear disc;

measure the loss of mass and/or the loss of volume of the specimen.

BRIEF DESCRIPTION OF THE FIGURES

For an easier understanding, the figures are attached, which represent preferred embodiments that are not intended to limit the object of the present description.

Figure 1 illustrates the schematic representation of a block-on-disk tribometer embodiment, in which:

1. represents a load application system bar;

2. represents a drive set;

3. represents a support of the sample (block);

4. represents a rotating disk;

5. represents a support for applying weights.

Figure 2 illustrates the schematic representation of a block-on-disk tribometer embodiment, in which:

1. represents a load application system bar;

2. represents a drive set;

3. represents a sample holder (block);

4, represents a rotating disk;

5. represents, a support for applying weights;

6. represents additional weight.

DETAILED DESCRIPTION

The present invention relates in particular to a block-on-disk tribometer comprising the following elements; load application system bar (1), drive assembly (2), specimen holder (block) (3), rotating disc (4) and weight application holder (5).

In one embodiment, Figure 1 illustrates the schematic representation of a block-on-disk tribometer, comprising a bar of the load/force application system: (1), wherein the bar comprises a load ratio of 1:4 with respect to weight applied to the weight application support (5), it is also constituted by a drive assembly (2) which contains a motor connected to a shaft that sets the disc (4) in rotation, and a support for the sample (3) which allows easy change of samples and restricts their rotation during the test because it has two guides.

In one embodiment, it is necessary to manufacture the disc and the sample (block) of the material to be tested with the appropriate dimensions and taking into account the test conditions. Then, the tribometer is connected to the electric current as well as the motor and the rotation speed is regulated using a potentiometer. Once the rotation speed is adjusted, the motor is turned off and the disc is placed on the shaft and the specimen (block) in the appropriate support. Afterwards, the engine starts again, waiting for it to reach the regulated rotation speed. Finally, the desired load is applied and the test begins. To finish the test, just turn off the engine when the test time is reached.

In one embodiment, the block-on-disk tribometer is a machine that allows wear tests to be carried out between two surfaces in contact, on various materials, namely metals, polymers, ceramics, composites,

In one embodiment, the tribometer also has the versatility of being able to evolve into other contact configurations, namely, linear (disk-disk and punctual sphere-disk.

Below are some application examples that are not limited to any other application: wear tests on materials, namely, metals, polymers, ceramics, composites, etc.

This tribometer makes it possible to measure the wear of the material, to later try to relate it to its use in everyday life, which is quite applicable in industry where one wants to know tribological parameters.

It should be noted that the block-on-disk tribometer prototype has already been used in tests with samples (blocks) of commercial pure aluminum having steel disk construction as antagonist.

term comprises or comprising when used in this document is intended to indicate the presence of the mentioned features, elements, integers, steps and components, but does not preclude the presence or addition of one or more other features, elements, integers, steps and components, or groups thereof.

The described embodiments are combinable with each other.

Aveiro, March 26, 2019

Claims (10)

1. Tribometer for measuring the tribological parameters of a specimen by wear tests characterized by comprising: a wear disc (4) for contacting the specimen, a specimen holder (3) for guiding the specimen onto the wear disc (4), a bar for applying articulated load (1) between two positions, a first position for applying load on the specimen against the wear disc (4), and a second position removed from the specimen, and a drive means (2) of the disc, wherein the specimen holder (3) comprises two guides to guide the specimen slides over the wear disc to prevent rotation of the specimen when subjected to wear by the disc (4). A tribometer according to the preceding claim, wherein the articulated bar (1) has an arm extending beyond the specimen to apply a leveraged load on said specimen. Tribometer according to any one of the preceding claims, wherein the articulated bar (1) has an arm extending beyond the specimen configured to receive a weight to apply an additional lever load on said specimen. Tribometer according to any one of the preceding claims, wherein the articulated bar (1) has an arm which extends beyond the specimen, with a weighting support (5) to receive a weight to apply an additional load. lever on said specimen. Tribometer according to any one of the preceding claims, wherein the load-applying bar (1) has a load ratio between 1:3 and 1:5, in particular 1:4. Tribometer according to any one of the preceding claims, wherein the disk drive motor means (2) comprises a shaft motor for rotating the wear disk. A tribometer according to any one of the preceding claims, wherein the load-applying bar (1) is made of steel. A tribometer according to any one of the preceding claims, comprising an element of circular section for transmitting load from the bar to the specimen. 9. A method of operating the tribometer for measuring tribological parameters of a specimen by wear tests according to any one of the preceding claims characterized in that it comprises: apply load to the specimen against the wear disc (4), wherein the two specimen holder guides slide the specimen over the wear disc to prevent rotation of the specimen when subjected to wear by the disc (4), and wherein the load application bar (1) is pivoted to one of two positions, a first position for applying a greater load of the specimen against the wear disc, or a second position withdrawn from the specimen for applying a lesser load of the specimen against the wear disc; measure the loss of mass and/or the loss of volume of the specimen. 10. Use of the tribometer to measure tribological parameters of a specimen by wear tests according to any one of claims 1-8 characterized in that it is used to measure friction coefficient, friction force, wear mass, and/or wear volume .